Around 5:20 p.m., deputies responded to a rollover involving a Toyota Tacoma at milepost 3, near Littlefield, Ariz. The driver, 59-year-old Elizabeth Lee Nielsen of Washington City, was airlifted by Mercy Air to University Medical Center in Las Vegas, Nev., where she was treated for significant muscle tissue damage to her lower leg. The vehicle was towed from the scene.

Nielsen was the sole occupant of the vehicle and was wearing a seat belt. The accident remains under investigation; speed appears to be a factor.